In 1959, an alien experiment crashes to Earth, releasing parasitic slugs that infect a young man, who is then cryogenically frozen at a university laboratory. Jumping to 1986, two college undergraduates, Chris and J.C., both struggling with personal issues, attempt to pledge a fraternity to impress Chris' crush, Cynthia. As part of a hazing ritual, they are instructed to steal a cadaver from the university's morgue. In the process, they accidentally release the cryogenically preserved body from 1959, now reanimated by the alien slugs. Chaos ensues as the resurrected corpse begins infecting others, turning them into zombie-like hosts for the parasitic creatures.

As the infection spreads, Chris, J.C., and Cynthia find themselves in a desperate fight for survival, uncovering the nature of the alien threat and uniting with a hard-nosed, haunted cop named Detective Cameron. The group realizes they must destroy the slugs before they can overrun the town. With time running out, they prepare for a final, explosive confrontation, determined to stop the infected and prevent the further spread of the horrific parasites. Events reach a fever pitch as the young heroes confront seemingly insurmountable odds in their quest for survival.